Neonatal Screening

Introduction

The physician must know which diseases are screened at birth in the state of Illinois and what mechanism are utilized to inform the physicians and parents of the results. It is imperative that the pediatrician check the State Screening results on all patients that they follow and record the resuts in the infants chart. The physician must also be knowledgeable of what to do when a test comes back abnormal.

The state of Illinois screens for a number of diseases (detailed below), including endocrinopathies, inborn errors of metabolism, and hemoglobinopathies. Screening is performed at 25 hours of life, and results are typically received within a few weeks.

Case 1

You get called by the state lab that one of your patients tested positive for galactosemia on a specimen submitted in the nursery. How should you proceed?

Initially you should make sure the patient is well. A visit with the pediatrician should be arranged to examine the neonate (early symptoms of galactosemia include lethargy, irritability, and failure to thrive) and discuss the implications of the result with the parents. A confirmatory test will be required, and it is important to put the infant on a lactose-free formula—the most common lactose-free formulas are made with soy protein isolate, such as Similac Isomil and Enfamil ProSobee. Nursing must be stopped as well.

If the confirmatory test is positive, the child should be maintained on the lactose-free diet and referred to a geneticist or metabolic specialist, as well as a dietician. If the test is negative, the infant can go back to breastfeeding or a milk based formula.

Patients also require calcium supplementation, since they cannot tolerate milk.

Case 2

You are informed that the screening test on one of your patients was abnormal with an elevated 17-OH Progesterone level. What should you do after being notified?

First, Google 17-hydroxyprogesterone. (It’s CAH, remember?)

The screening result needs to be confirmed, but the first priority is the patient. Patients may present with symptoms similar to sepsis, with poor feeding, lethargy, vomiting, and evidence of salt wasting and shock. The infant should be checked for evidence of virilization, primarily ambiguous genitalia. In 21-CAH, BMP will demonstrate hyponatremia and later hyperkalemia. If the confirmatory test is positive, the patient should be referred to an endocrinologist.

Treatment for CAH consists of long-term glucocorticoid and mineralocorticoid replacement.

Hemoglobinopathies-should refer to a hematologist for further evaluation

Hypothyroidism- abnormal test must be repeated. Most commonly due to congenital absence of the thyroid gland. Refer to endocrinologist.

Phenylketonuria- if positive should be repeated and if remains positve, special diet without phenylalanine should be started. Also refer to a metabolic disease specialist.

Hearing

Beginning in July 2002, mass spectroscopy newborn screening has begun in Illinois. http://www.idph.state.il.us/HealthWellness/disorderlist.htm This testing will detect 25 individual disorders: amino acid disorders, organic acid disorders, and fatty acid oxidation disorders. Results are classified as "presumptive positive" and "borderline positives". A presumptive positve has a 1/4 chanice of being a true positive and borderline positives will be normal in about 95% of the cases. The physician will be notified by the state Newborn Screening Program if there is a presumpitive postive and an information sheet and consultant list will be forwarded by fax. It is the respoonsibility of the physician to notify the family, determine the clinical status of the newborn, and and refer the neonate to the proper consultant.

Borderline positive results will be mailed to the physician and and they must still contact the familiy and determine the clinical condition of the neonate. If necessary, the patient should be referred to a consultant.

Retesting and consultant fees are covered by the State. Special formulas and foods are also covered by the State.

Turnaround times have averaged 11 days with most of the delays occurring between the time of colloection and reception at the State Lab.